Spark-plug.



D. W. PECK.

SPARK PLUG.

APPLICATION FILED JAN.10, 1912 Patented Dem 28,1915.

INVENTOR afl- ATTORNEYS WiTNESSES:

DUNCAN W. PEGK, OF SYRACUSE, NEW YORK.

SPARK-PLUG.

Specification of Letters Patent.

Patented Dec. 28, 1915 Application filed January 10, 1912. Serial No. 670,411.

To all whom it may concern Be it known that I, DUNCAN W. PECK, of Syracuse, in the county of Onondaga and State of New York, have invented a certain new and useful Spark-Plug, of which the following is a specification. I

This invention has for its object the production of a particularly simple and etficient spark plug, and it consists in the combinations and constructions hereinafter set forth and claimed. I

In describing this invention reference is had to the accompanying drawing in which like characters designate corresponding parts in all the views.

Figure 1 is a longitudinal sectional view of one form of this spark plug. Fig. 2 is a sectional View on line A-A, Fig. 1. Figs. 3, 4 and 5 are sectional views of other forms of my spark plug.

1 is the body of the spark plug, the body being provided with external threads 2 for turning into a threaded opening of the cylinder of an engine. Said body 1 is formed with a lengthwise axial passage 3 having its outer or upper end closed by a bushing 4 threading thereinto, the bushing terminating short of the inner end of the body, forming a recess. This bushing is formed wlth an axial opening decreasing in diameter toward its outer or upper end. The bushing 4 is provided with a flange 5 opposed to the upper face of the body 1, and an annular packing 6'is interposed between said flange 5 and the upper face of the body 1.

The central electrode or terminal of the spark plug extends axially through the bushing 4 and comprises outer and inner sections 7 and 8 arranged end to end, the outer section 7 being formed with a lengthwise passage 9 opening through the inner end face thereof, said passage usually eX-' tending axially of the section 7 the full length thereof. The section 7 is also formed with a plurality of transverse slots 10 opening through its inner end face and also into the passage 9, the slots 10 being usually arranged in transverse radial, alinement, and two of the slots opening through diametrically opposite points of the periphery of the section 7 and the other two slots extending at a right angle to the first-mentioned slots and opening through the periphery of the section 7. These slots are usually formed by sawing the inner end of the section 7 along diameters arranged at a right angle to each other. The forming of such transverse slots or passages, as set forth, is much more economical than boring passages communicatmg with the central passage.

One end of the section 8 is forced into the bottom of the passage intersected by the slots 10 and terminates short of the bottoms 11 of the slots so that the fluid inserted through the passage 9 will have an outlet through the transverse'slots or passages into the recess 3. The fluid forced through said passage 9 clears the passage and the terminals of the plug of any soot deposited and flows to the end of the section 8 to insure ignition within the cylinder by a spark between the lower end of the section 8 and the other electrode 12 which projects from the lnner end of the body and across the recess 3. The slots 10 in effect form prongsat the inner end of the section 7; and the inner section 8 extends between these prongs and is held in position thereby with its contiguous end face spaced apart from the horizontal plane of the bases of the prongs and of the bottoms of the slots. The slots constitute the spaces between the prongs and the lengthwise passage 9 opens into said spaces at the intersection thereof.

13 is a sleeve of insulation decreasing in diameter toward its outer or upper end and fitting the axial opening of the bushing 4, said sleeve encircling the section 7 of the central electrode and projecting beyond the inner end of the same forming an annular chamber 14 around the inner or upper end of the section 8 against the walls of which impinges the fluid projected from the slots 10. 3

Preferably my spark plug is so formed 1 that no chamber or socket in which soot can accumulate, intervenes between the periphcry of the lower end of the sleeve 13 and the inner face of the body 1 and usually the bushing 4 is formed with an integral extens1on 15. However, as seen in Figs. 3, 4 and 5 the annular space between the periphery of the lower end of the sleeve of insulation 13 and the inner face of the body .1 may be filled by an additional sleeve of insulation 16 forming an extension of the bushing, the lower end edge of the sleeve 16 being flush with the lower edge of the sleeve 13. As

seen in Fig. 3 said sleeve 16 may be held in position by an annular shoulder provided on the inner face of the socket 3 and such shoulder may consist of a ring 17, Fig. 3, sprung into an annular groove 18 provided in the walls of the recess 3, or as seen in Fig. A may be a projecting annular shoulder 19 formed integral with the Walls of the socket 3, or as seen in Fig. 5 said shoulder 19 may be in the form of a ledge 20 facing upwardly and provided by forming the lower portion of the recess 13 of less. diameter than the portion in which the bushing 4 is arranged.

21 is a sleeve or block of insulation having an axial opening decreasing in diameter toward its upper end and fitting the portion of the sleeve 13 above the bushing 41. The lower end of the sleeve 21 is mounted on the upper face of the bushing 4.- and the upper end of said sleeve 21 forms a seat for the nut like base 22 of a cup 23 screwing on the reduced upper or outer end 2% of the section 7 of the central electrode. The body of the cup is formed spherical for receiving that type of wire terminals or binding .de vices designed to grasp or fit spherical bniding posts. Other formsof termlnals. as the forked type may be attached to the plug by clamping the same between the base 22 of said cup and the opposing surfaces of the contiguous parts of the spark plu 25 isa plug screwing into the cup 23 and serving as a closure therefor, and for the passage 9 of the section 7 of the central electrode, the plug being formed with a conical inner end 26 which seats near its point'against a beveled seat 27 at the upper end of the passage '9, the remalnlng area of theconical end 26 being spaced apart from the rounding bottom 28 of the cup 23. The

plug 25 is formed with an inclined passage 29 therefor, the lower end of which'is out of alinement with the passage 9 and opens through a portion of the conical surface spaced apart from the bottom 28 v of the cup 28.

A spark plug constructed as described is particularly advantageous in that the sections of the central electrode can be cheaply assembled and the transversepassages or slots of the upper section can be quickly and cheaply formed therein.

What I claim is: l. A spark plug comprising a central electrode including inner and outer sections arranged end to end, the outer section being formed with a lengthwise passage and with prongs at its inner end, the passage opening into the spaces between the prongs, and the inner section having one end thereof extended between the prongs and frictionally held in position thereby with its contiguous end face spaced apart from the horizontal plane of the bottoms of the spaces between the the inner face of the prongs, whereby lateral passages are provided from the lengthwise passage, substan-, tially as and for the purpose specified.

2. A spark plug comprising a central electrode including inner and outer sections arranged end to end, the outer section being formed with a lengthwise passage and with prongs at its inner end, the spaces between the prongs intersecting, and the inner end of the lengthwise passage opening into the intersection of the spaces, and the inner section of the electrode having one end extending between the prongs at the intersection of the spaces between the same, substantially as and for the purpose set forth.

3. A spark plug comprising a central electrode including inner and outer sections arranged end to end, the outer section being formed with a lengthwise axial passage and with a plurality of prongs at its inner end, the prongs being arranged so that the spaces between the same extend substantially diametrically of the inner end of said outer section, said axial passage opening into said.

spaces, and the inner section of the electrode having one end extending between the prongs in alinement with the passage, substantially as and for the purpose described.

4. A spark plug comprising a central electrode including inner and outer sections arranged end to end, the outer section being formed with a lengthwise passage, and with a plurality of prongs atits inner end arranged so that the spaces between the prongs extend diametrically of the inner end of the outer section and intersect at the horizontal axis thereof, said lengthwise passageopening into the spaces between the prongs at the intersection thereof, and the inner section having one end extended between the prongs at the intersection of the spaces beclrcling the lower end of the slecse of insulation and gttling the space between the periphery oi e lower end of such sleeve and passage of the body, and a central electrode arranged within the sleeve of insulation, substantially as and for the purpose set forth.

6. A spark plug comprising a body formed with an axial passage, a bushing formed with an axial passage arranged in the upper portion of the body and terminating short of the lower end of the body forming a recess, a sleeve of insulation arranged in the axial passage of .the bushing and the bushing being provided with an integral extension, the end face of which is flush with the edge face of the-sleeve of insulation, and a of Onondaga, in the State of New York, central terminal within the sleeve of insulathis 7th day of Dec, 1911.

tionsaibstantially as and for the purpose de- DUNCAN W PEGK .scrl In testimony whereof, I have hereunto Witnesses:

signed my name in the presence of two at- S. DAVIS,

testing witnesses, at Syracuse, in the county F. B. Surrn. 

